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datagrams over an IP network. It is used primarily for broadcast-

ing messages over a network. In medical imaging, UDP is used to

log information from various devices to a system logging reposi-

tory. A datagram is a piece of a message transmitted over a pack-

et-switching network, and is a packet of information that con-

tains the destination address in addition to data.

• Channel 1: GPCLK/UART—This channel can be used as a general

purpose clock (GPCLK) or universal asynchronous receiver-trans-

mitter (UART). See Channel 3 for a more detailed description.

• Channel 2: Infrared Data Association (IrDA) is a group of device

manufacturers that developed a standard for transmitting data via

IR light waves. Increasingly, computers and other devices (such as

printers) come with IrDA ports. This enables you to transfer data

PDA Robotics

Figure 1.4

Block diagram of the Intel StrongARM SA-1110 microprocessor.

PDA 01 5/30/03 9:09 AM Page 8

from one device to another without any cables. For example, if

both your laptop computer and printer have IrDA ports, you can

simply put your computer in front of the printer and output a doc-

ument, without needing to connect the two with a cable.

IrDA ports support roughly the same transmission rates as tradi-

tional parallel ports. The only restrictions on their use are that

the two devices must be within a few feet of each other, and there

must be a clear line of sight between them. The IrDA port on the

PDA will be the main communication link to PDA-Bot; in

essence, it will be the spinal cord. PDA Robot responds to IrDA

discovery requests and identifies itself as “generic IrDA.” I decid-

ed to use an IrDA data link to the Robot because it is a very reli-

able communication link (error correction is built into it) that

requires absolutely no cables!

See: Chapter 4: Infrared Communications Overview, PDA Bot IR

transponder.

• Channel 3: Universal asynchronous receiver-transmitter (UART):

Intel provides a development board for the StrongARM SA-1100

microprocessors. It is interesting to note that most PDAs using

the StrongARM are almost identical in function to that of the

development board.

Increasingly, ARM-based microprocessors are being used in Palm OS

devices such as the Tungsten (see Figure 1.5). It has a Texas Instruments

OMAP1510 processor (an enhanced ARM-based processor).

The OMAP1510 processor includes the following:

• TI-enhanced ARM9 up to 175 MHz (maximum frequency).

• TMS320C55x DSP up to 200 MHz (maximum frequency).

• Voltage: 1.5v nominal.

• Optimized software architecture that allows designers to leverage

dual processing, and provides a complete and seamless software

foundation.

• DSP/BIOS Bridge that provides a seamless interface to the DSP

using standard APIs allowing easy access to DSP multimedia

algorithms.

Chapter 1 / Anatomy of a Personal Digital Assistant (PDA)

PDA 01 5/30/03 9:09 AM Page 9

• Open platform that enables a large network of independent

developers to provide a broad range of OMAP compatible soft-

ware solutions.

• LCD control/frame buffer for 16-bit QVGA display.

• USB client and host control.

• MMC-SD support.

• Bluetooth interface.

• USB, uWire, camera, and enhanced audio codec interface.

• Small, 289-pin MicroStar BGA package eases design in space-

constrained devices.

PDA Robotics

Figure 1.5

Palm OS Tungsten.

PDA 01 5/30/03 9:09 AM Page 10

To provide the optimal balance of high performance and low power

consumption necessary for these devices, the OMAP1510 combines

the TMS320C55x DSP core with a TI-enhanced ARM925 processor.

The ARM architecture is well suited for control-type code, such as the

operating system and user interface. The C55x DSP provides the addi-

tional processing power to handle the compute-intensive operations

such as security, multimedia, and speech. This is a great chip for

PDAs. Figure 1.6 shows the extensively integrated OMAP microchip.

A final example of a system on a chip design is the popular

MC68EZ328 (DragonBall EZ) Integrated Portable System Processor

used in many of the PDAs currently in use. Even though these proces-

sors typically run at a slower clock rate, they are capable of perform-

ing 2.7 MIPS performance at 16.58 MHz processor clock, and 3.25

MIPS performance at 20 MHz processor clock—very impressive for

their size and cost!

The second member of the DragonBall family, the MC68EZ328, inher-

its the display capability of the original DragonBall processor, but fea-

tures a more flexible LCD controller with a streamlined list of periph-

erals placed in a smaller package. This processor is mainly targeted for

portable consumer products, which require fewer peripherals and a

more flexible LCD controller. By providing 3.3 V, fully static operation

in efficient 100 TQFP and 144 MAPBGA packages, the MC68EZ328

delivers cost-effective performance to satisfy the extensive require-

ments of today’s portable consumer market. A number of the Visor

handspring PDAs utilize the Dragonball processors. Figure 1.7 is the

block diagram of the MC68EZ328.

Most PDAs have their small size and expandability in common,

regardless of the processor or operating system. In the near future, we

will likely see enough power in the palm of your hand to make the

desktop computer obsolete! The prices of even the high-end PDAs

have dropped dramatically over the last year, and will likely continue

to do so. There are slews of very low-cost, used PDAs floating around

at auctions, garage sales and in the classified ads. Even a very low-end

PDA running at least Palm OS version 1.1 will be sufficient for this

project. Look around if you don’t have one, and you will likely find a

very good deal on a used PDA.

Chapter 1 / Anatomy of a Personal Digital Assistant (PDA)

PDA 01 5/30/03 9:09 AM Page 11

DSP

MMU

OMAP5910

32 32

Flash and

SRAM

memories

SDRAM

memories

SRAM

1.5M bits

MPU

interface

Memory interface

traffic controller (TC)

JTAG/

emulation

I/F

MPU core

(TI925T)

(instruction

cache, data

cache, MMU)

ETM9

LCD

I/F

OSC

Clock and reset management

System

DMA

controller

12 MHz 32 MHz

Clock Reset External

clock request

MPU

peripheral

bridge

TMS320C55x DSP

(instruction cache, SARAM,

DARAM, DMA,

H/W accelerators)

MPU Bus

MPU private peripherals bus

MPU public

peripherals bus

DSP private

peripheral bus

McBSP1

McBSP3

MCSI1

MCSI2

DSP public (shared) peripheral bus

DSP

private peripherals

timers (3)

Watchdog timer

level 1/2

interrupt handlers

DSP public peripherals

MPU/DSP shared peripherals

TIPB

switch

UART1

UART2

UART3 IrDA

Mailbox

GPIO I/F

MPU private peripherals

Timers (3)

Watchdog timer

Level 1/2 interrupt

handlers

Configuration registers

Device identification

MPU public peripherals

McBSP2

USB Host I/F

USB Function I/F

µWire

Camera I/F

MPUIO

32-kHz timer

PWT

PWL

keyboard I/F

MMC/SD

LPG x2

Frame adjustment

counter

HDQ/1-Wire

RTC

Figure 1.6

Block diagram of an OMAP processor.

PDA 01 5/30/03 9:09 AM Page 12

Chapter 1 / Anatomy of a Personal Digital Assistant (PDA)

Figure 1.7

Block diagram of

the MC68EZ328.

PDA 01 5/30/03 9:09 AM Page 13

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PDA Robot consists of a robotic body and a PDA (handheld computer)

brain. This book will guide you through the creation of PDA Robot.

The project consists of mechanical, electronic, and software compo-

nents. Figure 2.1 shows PDA Robot roaming autonomously through

the house, capturing images when any motion is detected. The PDA

sitting on top is the machine’s main controller, receiving, analyzing,

and sending data to the robot body. The PDA is connected to a desk-

top computer that is monitoring the system, interpreting both data and

the video stream. The personal computer (PC) also acts as a control

station where the robot can be controlled remotely, based on the video

that is displayed.

The block diagram in Figure 2.2 is a high-level conceptualization of

PDA Robot. It doesn’t show the PDA connected to the wireless network.

Major Electronic Parts

Microchip MCP2150 IrDA

Standard Protocol Stack Controller

The MCP2150 is a cost-effective, low pin-count (18-pin), easy to use

device for implementing Infrared Data Association (IrDA) standard

wireless connectivity (see Figure 2.3). The MCP2150 provides support

for the IrDA standard protocol “stack” plus bit encoding/decoding.

Robotic

System

Overview

PDA 02 5/27/03 8:20 AM Page 15

PDA Robotics

Figure 2.1

PDA Robot.

Figure 2.2

Block diagram of

PDABot.

PDA 02 5/27/03 8:20 AM Page 16

Vishay TFDS4500 Serial Infrared Transceiver

The TFDU4100, TFDS4500 (Figure 2.4), and TFDT4500 are a family of

low-power infrared (IR) transceiver modules compliant to the IrDA

standard for serial infrared (SIR) data communication, supporting

IrDA speeds up to 115.2 kb/s. Integrated within the transceiver mod-

ules is a photo PIN diode, infrared emitter (IRED), and a low-power

analog control integrated circuit (IC) to provide a total front-end solu-

tion in a single package. Telefunken’s SIR transceivers are available in

three package options, including our BabyFace package (TFDU4100),

once the smallest SIR transceiver available on the market. This wide

selection provides flexibility for a variety of applications and space

constraints. The transceivers are capable of directly interfacing with a

wide variety of I/O chips, which perform the pulse-width modula-

tion/demodulation function, including Telefunken’s TOIM4232 and

TOIM3232. At a minimum, a current-limiting resistor in series with

the IRED and a VCC bypass capacitor are the only external compo-

nents required to implement a complete solution.

Chapter 2 / Robotic System Overview

Figure 2.3

MCP 2150 chipset.

Figure 2.4

The vishay

TFDS4500.

PDA 02 5/27/03 8:20 AM Page 17